In accordance with the demand for a larger storage capacity of optical recording media (including magneto-optical storage medium) as typified by DVDs, there is an approach to shorter wavelengths of the optical source used for recording and reproduction as well as reducing the convergent point corresponding to light from a semiconductor laser focused onto a recording medium through a condenser lens. For such a condenser lens is employed glass such as quartz, an oxide such as sapphire, diamond, or the like, exhibiting low absorption with respect to light at a wavelength in the ultraviolet range to the deep ultraviolet range (200 nm to 350 nm). Japanese Patent Laying-Open No. 2003-161801 (Patent Document 1) proposes a fluoride optical material such as BaF2 (barium fluoride), CaF2 (calcium fluoride), LiF (lithium fluoride), and NaF (sodium chloride).